Method for manufacturing footwear, footwear produced using said method, and machine for manufacturing footwear

ABSTRACT

A method for manufacturing an article of footwear, the article of footwear comprising at least one shell, the shape of which is set by external heating, the manufacturing method comprising a reference step in which a first shell is positioned on a last, the first shell comprising at least one at least partially hot-melt or thermoformable material, the last extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a base to a top. The manufacturing method comprises at least one manufacturing step, subsequent to the reference step, the manufacturing step comprising at least one operation of hot-pressing at least a portion of the surface of the first shell arranged on the last.

BACKGROUND 1. Field of the Invention

The invention relates to a method for manufacturing an article of footwear comprising synthetic materials. The invention also relates to an article of footwear obtained by the method, and to a machine for manufacturing the article of footwear.

2. Description of the Background

Articles of footwear, such as shoes, are conventionally made by combining an upper and a sole assembly. The upper generally includes a number of parts, such as a lateral quarter, a medial quarter, a vamp, a tongue, a heel, a rear counter, a protective toe-cap, a tightening device including keepers and a lace, an inner lining, and may even have additional parts. Moreover, some of these parts may include a plurality of portions. The main problem with a conventional shoe is in assembling and turning parts that are cut and assembled flat into a three-dimensional shape. Conventionally, the upper is associated with a lasting sole to demarcate a footwear element.

According to a first method, the upper is glued to the lasting sole using an adhesive layer. The lasting sole, also referred to as the lasting board, is relatively rigid to withstand the assembly process. The gluing operation is carried out by pulling the upper and pressing it flat onto the lasting board, with a last being inserted in the upper. This is known as the traditional shoe lasting assembly. This technique makes it possible to exert sufficient pressure while heating the adhesive in order to obtain the footwear element.

A second method, also known, involves obtaining the footwear element by stitching the upper to the lasting board. This is referred to as the Strobel assembly. The lasting board in this case is a flexible stitchable sole, referred to as the Strobel sole.

For each of the first and second methods, the lasting board is integral with the sole assembly. The sole assembly further comprises external parts, such as one or more damping layers and a wear layer adapted to contact the ground, which are generally attached using an adhesive to the lasted board and upper. The sole assembly further comprises one or more inner layers arranged in the footwear element to fulfill protective functions in terms of hygiene, shock-absorption, foot arch support, or the like.

Finally, the association of the footwear element with the other constituent parts of the sole assembly forms the shoe.

Irrespective of the method used for its manufacture, a conventional shoe has certain disadvantages. First, the shoe uses a large number of parts, typically between forty and sixty. Such a large number of shoe-forming parts increases the number of manufacturing operations and the time required to carry out such operations. It usually takes forty minutes to one hour and thirty minutes to make a shoe. It can be said that shoes manufactured using conventional techniques are complicated, both by the number of their constituent parts and the number of manufacturing operations.

Another disadvantage results from the structural discontinuity of the shoe, in particular in the area of the upper. For example, a part of reduced size superimposed on another, larger part, may considerably modify the bendability of the upper in the location of the small part. This may hinder a user and also make the shaping, i.e., three-dimensional shaping, of the upper more difficult.

A further disadvantage is due to the presence of free spaces between the foot and the shoe. This means that the foot is not in contact with the upper or the sole assembly in certain locations. This is especially true in the area of certain portions of the junction between the upper and the lasting board. As a result, undesired displacements occur sometimes between the foot and the shoe, which can cause discomfort or injuries.

Finally, it can be said that a conventional shoe does not always ensure adequate support and/or tightening of the foot, or does not always provide satisfactory comfort for the foot. Moreover, such conventional shoe does not systematically conform to all foot deformations.

SUMMARY

In view of the foregoing, the present invention provides a new footwear construction method, in which the article of footwear comprises a first shell extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a base to an upper end, the first shell comprising yarns linked to one another mechanically, at least a portion of the yarns comprising at least one hot-melt filament. The yarns comprising at least one hot-melt filament are distributed over the entirety of the first shell, and the shape of the first shell is set by the melting of the yarns comprising at least one hot-melt filament.

As a consequence of this arrangement, the first shell can be shaped to have a geometry that is very similar to that of a foot, and thereby closely conforms to the shape of the foot in a very uniform fashion. This means that the foot is in contact with, or at least very close to, the first shell. This results in an evenly distributed support of the foot, with very few or no undesired displacements between the foot and the first shell. A resulting advantage is increased comfort of the article of footwear according to the new construction method, compared to a conventional shoe.

Another consequence of the arrangement according to the new construction method is that the first shell has structural continuity, in the sense that its inner surface and/or outer surface are substantially uniform. Physical properties of the first shell, such as bending, for example, can vary depending on zones of the shell. This results in less discomfort for the user.

The synthesis of the foregoing shows that the first shell supports the foot and provides adequate comfort therefor. Furthermore, the first shell is capable of conforming to the foot deformations. This enables the article of footwear to fit comfortably in any situation, be it a static or a dynamic situation.

A further consequence of the new construction method is the reduced number of parts required to manufacture the article of footwear, although the latter can be provided with a few additional parts. The first shell in itself is a minimalist assembly compared to a conventional footwear element. The first shell of the new construction method is a unitary element which, by itself, replaces at least the lateral and medial quarters, a vamp, a tongue, a rear counter, a lasting board, or even more parts. As a corollary, the new construction method significantly reduces the number of manufacturing operations and the time required to carry them out. The resulting advantage is that the article of footwear is much simpler, in any sense, than a conventional shoe. The structural simplicity of the new construction method does not reduce the number of technical functions performed by the article of footwear, compared to a conventional shoe. Paradoxically, it can even be said that the structural simplicity is a source of technical improvements in terms of quality and quantity. The new construction method is therefore advantageous and promising.

In view of the foregoing, the invention generally further improves the manufacture of an article of footwear comprising at least one shell, in which the shape of the at least one shell is set by external heating. In particular, the invention further improves quality, in the sense that manufacturing defects are substantially or completely avoided. The invention makes the manufacturing process even simpler, faster and more economical.

Accordingly, the invention provides a method for manufacturing an article of footwear that comprises at least one shell, the shape of which is set by external heating, the manufacturing method comprising a reference step in which a first shell is positioned on a last, the first shell comprising at least one at least partially hot-melt or thermoformable material, the last extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a base to a top.

The manufacturing method according to the invention comprises at least one manufacturing step subsequent to the reference step, the manufacturing step comprising at least one operation of hot-pressing at least a portion of the surface of the first shell arranged on the last.

It is shown below that, for at least one embodiment of the invention, the first shell comprises yarns linked to one another mechanically.

The first shell is hot-pressed as it is positioned on the last. This causes a change of state and/or adhesion of the hot-melt or thermoformable material(s) at the same time as the hot-pressing of at least a portion of the first shell. One of the resulting effects is that this portion retains the geometry of the pressed portion of the last, or of the entire last in the case in which hot-pressing is applied everywhere. In other words, the article of footwear acquires its final geometric appearance directly during hot-pressing. The resulting advantages include simplicity and manufacturing speed, as well as low cost of the article.

As a corollary, and still with the aim of improving the manufacture of an article of footwear, the invention provides a machine for implementing the method mentioned above. More specifically, the invention provides a machine for manufacturing an article of footwear, the machine comprising at least one manufacturing station arranged to perform at least one manufacturing operation on a last, the last extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a base to a top.

The machine according to the invention includes a step of hot-pressing at least a portion of the surface of the last.

The machine implements the aforementioned method in the sense that the first shell positioned on the last is hot-pressed during pressure on the last. Here again, for example, this causes a change of state and/or adhesion of at least a portion of the first shell at the same time as pressure is applied. One of the resulting effects is that this portion retains the geometry of the pressed portion of the last, or even of the entire last, in the case in which hot-pressing is applied everywhere. In other words, the machine provides the article of footwear with its final geometric appearance directly during hot-pressing. The resulting advantages once again include simplicity and manufacturing speed, as well as low cost of the article.

In general, it can be said that the manufacturing method and the machine for implementing such method improve the manufacture of an article of footwear.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will be better understood from the following description, with reference to the annexed drawings which illustrate how the invention can be embodied, and in which:

FIG. 1 is a perspective front view of an article of footwear, obtained by the manufacturing method according to the invention;

FIG. 2 is a perspective schematic view of a preform used for making a first shell and a second shell of the article of footwear of FIG. 1;

FIG. 3 is a perspective front view of a reinforcement intended to be integrated into the article of footwear of FIG. 1;

FIG. 4 is a schematic view related to the constitution of a shell of the article of footwear of FIG. 1;

FIG. 5 is another schematic view related to the constitution of a shell of the article of footwear of FIG. 1;

FIG. 6 is yet another schematic view related to the constitution of a shell of the article of footwear of FIG. 1;

FIG. 7 is a side view related to the manufacture of the article of footwear of FIG. 1;

FIG. 8 is a perspective view related to the manufacture of the article of footwear of FIG. 1;

FIG. 9 is another perspective view related to the manufacture of the article of footwear of FIG. 1;

FIG. 10 is a schematic top view of a manufacturing station of a machine for implementing the method according to the invention, the station being arranged to perform an operation of hot-pressing the rear end of a last, and an operation of hot-pressing the front end of the last;

FIG. 11 is a schematic view of one side of the station according to FIG. 10;

FIG. 12 is a schematic view of another side of the station according to FIG. 10;

FIG. 13 is an enlarged partial view of FIG. 11, in a case in which no pressure is exerted on the last;

FIG. 14 is similar to FIG. 13, in a case in which pressure is exerted on the last;

FIG. 15 is a schematic side view of another manufacturing station of the machine, the station being arranged to perform an operation of hot-pressing a lateral side of the last, and an operation of hot-pressing a medial side of the last;

FIG. 16 is a schematic view of another side of the station according to FIG. 15;

FIG. 17 is an enlarged partial view of FIG. 15, in a case in which no pressure is exerted on the form;

FIG. 18 is similar to FIG. 17, in a case in which pressure is exerted on the last;

FIG. 19 is a schematic top view of another manufacturing station of the machine, the station being arranged to perform an operation of hot-pressing the base of the last, and an operation of hot-pressing the top of the last;

FIG. 20 is a schematic view of one side of the station according to FIG. 19;

FIG. 21 is a schematic view of another side of the station according to FIG. 19;

FIG. 22 is an enlarged partial view of FIG. 20, in a case in which no pressure is exerted on the last;

FIG. 23 is similar to FIG. 22, in a case in which pressure is exerted on the last;

FIG. 24 is a longitudinal cross-sectional view of a head provided to exert the hot-pressing, the head having an elastically deformable portion;

FIG. 25 is an external view of the head of FIG. 24, from the side of an active surface;

FIG. 26 is a longitudinal cross-sectional view of another head provided to exert the hot-pressing, the head here also having an elastically deformable portion;

FIG. 27 is an external view of the head of FIG. 26, from the side of an active surface;

FIG. 28 is a top view of a machine for an embodiment according to which the distribution of the manufacturing stations is horizontal;

FIG. 29 is a view of one side of the machine according to the embodiment of FIG. 28; and

FIG. 30 is a side view of a machine according to one of claims 16 to 27, for an embodiment according to which the distribution of the manufacturing stations is vertical.

DETAILED DESCRIPTION

First, an article of footwear, and then a manufacturing method and machines for implementing the method, are described below with reference to all of the drawing figures.

As described below, the article of footwear is non-limitingly adapted for walking or running on flat or mountainous terrain. However, other fields of application are possible, such as ball-playing sports, racquet sports, or the like.

As shown in FIG. 1, an article of footwear 1 is provided to receive the foot of a user. For convenience, the article of footwear 1 will be considered as a shoe in the following description although, as will be shown in detail, its structure is completely unusual. Thus, the shoe 1 extends lengthwise along a longitudinal direction L, between a rear end, or heel 4, and a front end, or tip 5, and widthwise along a transverse direction W, between a lateral side 6 and a medial side 7.

As shown, the shoe 1 comprises a lower portion 10, provided to surround the foot, and includes no upper portion. Alternatively, however, a shoe may be envisioned to include both a lower portion and an upper portion, the latter being provided to surround the ankle and possibly the lower leg. The shoe 1 extends heightwise from a base 12 to an upper end 13, that is to say, up to the free end of the lower portion 10. The base is a subdivision of the shoe, on which the foot takes support.

The shoe 1 is structured to allow good foot rolling movement during walking, transmission of sensory information, as well as forces when taking supports or jump landing. Therefore, the shoe 1, or article of footwear, is relatively flexible.

As can be seen in FIGS. 1 and 2, the shoe 1 comprises a first shell 21 extending lengthwise along the longitudinal direction L, from a rear end 24 to a front end 25, widthwise along the transverse direction W, between a lateral side 26 and a medial side 27, and heightwise from a base 28 to an upper end 29. This enables the first shell to surround and hold the foot of the user. For its construction, the first shell for example includes yarns linked to one another mechanically. In a non-limiting fashion, at least a portion of the yarns comprises at least one hot-melt filament, as described more clearly below. The first shell may also be made, not with yarns, but with any other material, the important thing being that it comprises a hot-melt material and/or a thermoformable material. The first shell 21 provides the shape of the shoe 1. The rear end 24, the front end 25, the lateral side 26, the medial side 27, the base 28 and the upper end 29 of the first shell demarcate the rear end 4, the front end 5, the lateral side 6, the medial side 7, the base 12 and the upper end 13, respectively, of the article of footwear or shoe 1. The minimalist structure used for the shell 21 ensures simplicity, lightness and other advantages, as described below.

The shoe 1 also comprises a second shell 31 extending lengthwise along the longitudinal direction L, from a rear end 34 to a front end 35, widthwise along the transverse direction W, between a lateral side 36 and a medial side 37, and heightwise from a base 38 to an upper end 39. The second shell 31 also covers the foot, as does the first shell 21. The second shell 31 is arranged outside of the first shell 21 and, thereby, indirectly covers the foot. The final shape of the shoe 1 is provided by both the first shell 21 and the second shell 31. The advantage of using two shells will be more apparent below.

Still in the context of the invention, the second shell 31 non-limitingly comprises yarns linked to one another mechanically. Here again, by way of example, at least a portion of the yarns comprises at least one hot-melt filament. Again, the second shell may also be made, not with yarns, but with any other material, the important thing being that it comprises a hot-melt material and/or a thermoformable material. The second shell 31 also provides the shape to the shoe 1. In other words, the rear end 34, the front end 35, the lateral side 36, the medial side 37, the base 38 and the upper end 39 of the second shell 31 also demarcate the rear end 4, the front end 5, the lateral side 6, the medial side 7, the base 12 and the upper end 13, respectively, of the article of footwear or shoe 1. The minimalist structure used for the shell 31 ensures simplicity, lightness, and a number of other advantages, as described below.

As shown schematically in FIG. 2, each shell 21, 31 is obtained by manufacturing a sleeve 41, that is to say, a flexible tube made, for example, of yarns linked to one another mechanically. The sleeve 41 is a preform for making the article 1. In a non-limiting fashion, the sleeve 41 makes it possible to obtain both the first shell 21 and the second shell 31. The sleeve 41 extends lengthwise from a first end 42 to a second end 43. The first end 42 is closed by any technique known to one with ordinary skill in the art, such as stitching after folding, the addition of an end piece made of yarns linked to one another mechanically, or any equivalent. The second end 43 is merely an opening.

The sleeve 41 makes it possible to manufacture the shells 21, 31 in one piece. Here, the first shell 21 and second shell 31 are coextensive. This simplifies manufacture by reducing the number of parts and the time required for implementation.

Before the sleeve 41 is described in more detail, it is useful to explain, especially with reference to FIG. 3, that the article of footwear 1, or shoe, can include a reinforcement 51. As described more clearly below, the reinforcement is fittingly associated with the shells 21, 31 at the time of manufacture of the shoe 1, in order to provide the latter with specific properties.

The reinforcement 51 is an element extending lengthwise from a rear end 54 to a front end 55, widthwise between a lateral side 56 and a medial side 57, and heightwise from a base 58 to an upper end 59. The reinforcement 51 has a length and a width similar to the lengths and widths of the shells 21, 31. More specifically, the reinforcement 51 extends, in relation to the first shell 21, lengthwise from the rear end 24 to the front end 25, widthwise between the lateral side 26 and the medial side 27, and heightwise from the base 28 to the upper end 29. By definition, this makes it possible to reinforce the first shell 21, and therefore the article of footwear 1, particularly in the area of the base 12 and at the periphery of the base. However, for this type of shoe, the reinforcement may be omitted.

The reinforcement 51 non-essentially carries a tightening device 61, visible in FIG. 1. The tightening device 61 includes keepers 62 located in the area of the upper end 59, as well as a lace 63 and a blocking device 64, known to one with ordinary skill in the art. It is therefore possible to tighten or loosen the reinforcement 51 and, thereby, to tighten or loosen the shoe 1, as is more apparent below.

The association of the yarns used to make the sleeve 41, and therefore the shells 21, 31, will now be described in more detail with reference to FIGS. 4 and 5. Generally speaking, the yarns are provided to be associated with one another using any suitable textile technique, such as knitting, weaving, braiding, or the like. In the case of knitting, it is possible to use a single- or double-knit circular knitting machine, a cylinder knitting machine, or a flat knitting machine. Two knitting zones may be joined to one another using the Intarsia knitting technique or embroidery. Various decorative patterns can be obtained directly when knitting with the Intarsia method, embroidery, the Jacquard knitting technique, or the like. FIG. 4 shows conventional weaving with first yarns 65 oriented along a first direction, second yarns 66 oriented along a second direction, the first 65 and second 66 yarns intersecting to form a flexible mesh. FIG. 5 shows knitting with three yarns 67, 68, 69 arranged in interpenetrating loops. However, a number of other arrangements are possible.

The sleeve 41 is manufactured, for example, with a flat knitting machine, which makes it possible to vary the cross section, that is to say, the diameter of the sleeve, to make shape variations for the heel, to create opening for passage of the laces, to vary the thickness of the wall of the sleeve, or in particular to vary the tightening of the loops. In fact, the flat knitting machine provides a wide range of adjustment possibilities, and it is adapted to make sleeves of all sizes, whether in diameter or in length. As such, the flat knitting machine is more practical than the circular knitting machine. Indeed, the circular knitting machine works on a reduced range in the area of the sleeve diameter. It is therefore necessary to use a plurality of different circular knitting machines to make a complete line of sleeves 41, that is to say, a complete line of shoes encompassing all shoe sizes, where a single flat knitting machine would be sufficient. In the end, a flat knitting machine makes it possible to make one or more three dimensional shells, with all desired features, and to the desired shoe size.

A yarn is next defined in the context of the invention.

First, the yarn may be a monofilament obtained, for example, by extruding a hot-melt synthetic material, such as polyamide, polyurethane, polyethylene, or any equivalent or similar material. The production of a filament is continuous, in a way comparable to silk filament produced by a spider. Specifically, the filament may be mono-component or mono-material, in the sense that its transverse cross section is uniform. But the filament may also be multi-component, e.g., bi-component. In this latter case, a transverse cross section of a filament shows a core comprised of a first material and a peripheral shell surrounding the core, such shell being comprised of a second material. Each material can be hot-melt, or only one material can be hot-melt. If both materials are hot-melt, their melting temperatures are different.

Next, the yarn may be multi-filament. In this case, it is obtained by associating a plurality of filaments. Such an association is shown using the diagram of FIG. 6. Here, all of the filaments 70 are of the same type, in the sense that each has the same melting point. However, combinations of filaments of various types can be provided, some of which may be meltable and others may not, or may have various melting points. The filaments are associated with one another by any known technique.

Also, the yarn can be obtained in the form of a fiber mesh. Here, a fiber is a filament of limited length. The fibers are associated in tight contact to form the mesh, by any known technique, and especially by twisting. Retaining the fibers to one another is traditionally done by friction, especially with natural fibers such as cotton. However, for the invention, retaining the fibers to one another occurs either by friction or by a combination of friction and melt-adhesion, or yet entirely by adhesion, because the invention uses hot-melt materials.

The general structure of the sleeve 41 having been presented, its use for the manufacture of the shoe 1 can next be explained. In fact, the constituent parts of the shoe 1 are assembled by hand, without complex and expensive machinery, in what constitutes a reference step.

It can be understood from FIGS. 7 to 9 that the sleeve 41 is slipped onto an element 73, referred to as a last, shaped to emulate the shape of the foot of a user. Specifically, the last extends lengthwise from a rear end 74 to a front end 75, widthwise between a lateral side 76 and a medial side 77, and heightwise from a base 78 to a top 79. The sleeve is applied to the last 73 in the manner of a sock on a foot. The sleeve 41 conforms to the shape of the last 73 due to its elasticity, which is due to its constitution. Then the reinforcement 51, according to the embodiment, is fitted on the subdivision of the sleeve 41 that becomes the first shell 21. This means that, in the reference step of the manufacturing method, and in a non-limiting fashion, a reinforcing structure 51 is positioned on the last. Then the subdivision of the sleeve 41 that becomes the second shell 31 is folded over the reinforcement 51, thereby covering the latter and the subdivision assigned to the first shell. This is sufficient to form the subassembly of the shoe 1 that envelopes the foot, a subassembly that ultimately includes the first shell 21, the reinforcement 51, and the second shell 31. It then suffices to subject the subassembly to a higher temperature, using any suitable technique, to melt the hot-melt filaments of the shells only as appropriate, and thus provide the shoe 1 with its geometry. After heating, the last 73 may be removed from the subassembly. The shoe 1 is then almost finished. It suffices to add an outer sole assembly 81 thereto. As shown in FIG. 1, the article of footwear 1, or shoe, includes an outer sole assembly 81. This outer sole assembly is adapted to take support on the ground and, therefore, is structured to resist wear by friction and also to damp impacts. It thus includes a wear layer 82 and a damping layer 83, for example. The shoe according to the invention is well suited, for example, for a long-distance runner.

As can be understood from FIGS. 1 and 2, but also with reference to FIGS. 7-9, the boundary between the first shell 21 and second shell 31 has a fold 84 demarcating a foot insertion opening 85. The periphery of the foot insertion opening 85 is therefore demarcated simply by folding the two shells 21, 31 on one another. This means that this periphery has no stitch or attached element and, therefore, that the shoe 1 does not cause discomfort to the user, including in the area of the opening 85.

The article of footwear 1 presented above is only one exemplary embodiment among a number of possibilities. However, this example is useful to better understand the manufacturing method and the machine for implementing the same, as explained below.

According to the invention, the manufacturing method comprises a reference step in which a first shell 21 is positioned on a last 73, the first shell 21 comprising at least one at least partially hot-melt and thermoformable material, the last 73 extending lengthwise from a rear end 74 to a front end 75, widthwise between a lateral side 76 and a medial side 77, and heightwise from a base 78 to a top 79. The manufacturing method comprises at least one manufacturing step subsequent to the reference step, the manufacturing step comprising at least one operation of hot-pressing at least a portion of the surface of the first shell 21 arranged on the last 73. The reference step is that which has been explained above in the description of the article footwear. Each manufacturing step is presented below. The first shell 21 non-limitingly comprises yarns 65, 66, 67, 68, 69 linked to one another mechanically.

With respect more specifically to the article of footwear structure, as has been explained, it is to be understood that in the reference step of the manufacturing method, a second shell 31 is positioned on the last 73, the second shell 31 comprising at least one at least partially hot-melt or thermoformable material, and that, in the manufacturing step, the hot-pressing operation is performed on at least a portion of the surface of the second shell 31 arranged on the last. Here again, the second shell 31 non-limitingly comprises yarns 65, 66, 67, 68, 69 linked to one another mechanically.

The first shell 21 and second shell 31 are simultaneously subject to hot-pressing, as both are positioned on the last 73. As a result, the manufacture of the article of footwear is simpler and faster than if the shells were pressed separately.

To apply the aforementioned pressure, the invention provides a machine, a plurality of embodiments of which are presented below with reference to FIGS. 10-30. A first embodiment of the machine is designated by the reference numeral 91, according to FIGS. 10-27, and 28 and 29, and a second embodiment of the machine is designated by the reference numeral 92, according to FIGS. 10-27, and 30. In fact, FIGS. 10-27 are schematic views for a detailed understanding of the manufacturing steps.

Generally speaking, it can be said that a machine 91, 92, used for the manufacture of an article of footwear 1 according to the invention, comprises at least one manufacturing station adapted to carry out at least one manufacturing operation on a last 73, the last extending lengthwise from a rear end 74 to a front end 75, widthwise between a lateral side 76 and a medial side 77, and heightwise from a base 78 to a top 79. The manufacturing operation includes a step of hot-pressing at least a portion of the surface of the last, or at least a portion of a shell positioned on the last. It should be understood here that it is possible to operate the machine in idle mode, that is to say, in the absence of a shell positioned on the last. During production, however, one or more shells are arranged on the last and thus subject to hot-pressing. This contributes to the implementation of the manufacturing method. In fact, the hot-pressing causes a more or less substantial melting of the yarns 65, 66, 67, 68, 69 involved in forming the shells 21, 31. After the melting, when the yarns return to room temperature, the article of footwear retains the appearance imparted by the last. In other words, the article of footwear 1 has its final dimensions, which enable it to receive a foot.

What has just been disclosed is particularly applicable to the article 1 described above. However, more generally speaking, the manufacturing method according to the invention is such that, in the manufacturing step, the hot-pressing causes a change of state and/or adhesion of some or all of the yarns of a shell. This means in particular that the manufacturing method can be implemented also in cases in which one or more shells are devoid of hot-melt yarns, or in cases in which they comprise hot-melt yarns only in certain zones.

To optimize the manufacturing method according to the invention, as will be seen below, at least one manufacturing step comprises two operations of hot-pressing at least a portion of the surface of the last 73. For at least one manufacturing step, two operations of hot-pressing at least a portion of the surface of the last 73 are performed simultaneously. For example, operations are provided to be performed to oppose the pressures to one another. This preserves the last 73 from constraints that might space it away from a desired reference position, because the resultant of the pressures is low, or zero. This actually balances the forces applied to the last. This contributes to improved reliability of the machine.

Still with respect to balancing the forces applied to the last 73, it is also seen below that at least one manufacturing step comprises at least one operation of holding the last.

As can be seen in particular in FIGS. 10-14, the machine 91 comprises a manufacturing station 95 arranged to perform an operation of hot-pressing the rear end 74 of the last 73, and an operation of hot-pressing the front end 75 and top 79 of the last. In the context of the invention, this characteristic also applies to any machine embodiment, as that designated by the reference numeral 92, which is described below. As a corollary, with the arrangement of the station 95, the manufacturing method includes a manufacturing step comprising an operation of hot-pressing the rear end 74 of the last, as well as an operation of hot-pressing the front end 75 and top 79 of the last 73. Because the first shell 21, the reinforcing structure 51 and the second shell 31 were positioned beforehand on the last 73, they are ultimately affixed to one another, in the areas of the rear end 4, front end 5, and upper end 13 of the article of footwear, by the melting of the yarns 65, 66, 67, 68, 69, as has been shown above. The affixing of the shells to one another, or of the reinforcement to one or all of the shells, can also be carried out using an adhesive. In addition to hot-pressing the rear end 74, front end 75 and top 79, the manufacturing station 95 is arranged to perform an operation of holding the base 78 of the last 73. As a corollary, the manufacturing method comprises an operation of holding the base 78 of the last 73. The holding is carried out at least partially during hot-pressing of the ends 74, 75 and top 79. This stabilizes the position of the last during application of the pressures.

Next, as can be observed in FIGS. 15-18, the machine 91 comprises a manufacturing station 96 arranged to perform an operation of hot-pressing the lateral side 76 of the last 73, and an operation of hot-pressing the medial side 77 of the last. As a corollary, the manufacturing method includes a manufacturing step comprising an operation of hot-pressing the lateral side 76 of the last 73, and an operation of hot-pressing the medial side 77 of the last 73. It is further considered that the first shell 21, the reinforcing structure 51 and the second shell 31 were positioned beforehand on the last 73. In this case, the first shell 21, reinforcing structure 51 and second shell 31 are ultimately affixed to one another, in the areas of the lateral side 6 and the medial side 7 of the article of footwear, also by the melting of the yarns 65, 66, 67, 68, 69. Here again, the affixing of the shells to one another, or of the reinforcement to one or all of the shells, can also be carried out using an adhesive.

To continue, with reference to FIGS. 19-23, the machine 91 comprises a manufacturing station arranged to perform an operation of hot-pressing the base 78 of the last 73, and an operation of holding the top 79 the last. As a corollary, the manufacturing method includes a manufacturing step comprising an operation of hot-pressing the base 78 of the last 73, and an operation of holding the top 79 of the last 73. It is again considered that the first shell 21, the reinforcing structure 51 and the second shell 31 were positioned beforehand on the last 73. In this case, the first shell 21, reinforcing structure 51 and second shell 31 are ultimately affixed to one another, in the area of the base 12 of the article of footwear, by the melting of the yarns 65, 66, 67, 68, 69. Here again, the affixing of the shells to one another, or of the reinforcement to one or all of the shells, can also be carried out using an adhesive.

The preceding can be summarized as follows. According to the embodiment discussed, considering again that this applies to any machine embodiment, the machine 91 comprises a first manufacturing station 95, arranged to perform an operation of hot-pressing the rear end 74 of the last 73, and an operation of hot-pressing the front end 75 and top 79 of the last, the machine comprises a second manufacturing station 96, arranged to perform an operation of hot-pressing the lateral side 76 of the last and an operation of hot-pressing the medial side 77 of the last, and the machine comprises a third manufacturing station 97, arranged to perform an operation of hot-pressing the base 78 of the last, and an operation of holding the top 79 of the last. Here again as a corollary, the manufacturing method comprises a first manufacturing step, the first manufacturing step comprising an operation of hot-pressing the rear end 74 of the last 73, and an operation of hot-pressing the front end 75 and top 79 of the last, the manufacturing method comprises a second manufacturing step comprising an operation of hot-pressing the lateral side 76 of the last, and an operation of hot-pressing the medial side 77 of the last, and the manufacturing method comprises a third manufacturing step comprising an operation of hot-pressing the base 78 of the last, and an operation of holding the top 79 of the last. In a non-limiting fashion, the three manufacturing stations 95, 96, 97 are provided to be arranged in this successive order. As a result, the manufacturing steps are carried out in this order. This has the advantage of low rejection rate.

FIGS. 10-23 and 24-27 next show more precisely how hot-pressing is exerted on the last 73, and thereby also on the constituent portions of the article footwear 1.

As can be seen in particular in FIGS. 13, 14, 17, 18, 22 and 23, for example, hot-pressing is exerted by a head 101 having an elastically deformable portion 102. For reasons of clarity, each of the heads of the machine 91 is designated by the reference numeral 101, although the heads have various structures. Similarly, each of the elastically deformable portions is designated by the reference numeral 102, although the portions have various structures.

As shown clearly in FIGS. 24 to 27, the head non-limitingly comprises a container 103 closed by a membrane 102, the membrane forming the elastically deformable portion, the container 103 housing a fluid 104. The container here is an enclosure having the appearance of an open box, that is to say, without a cover. In fact, it is the membrane 102 that closes the container 103, in order to retain the fluid 104 therein. The container is made, for example, with a rigid material such as metal, metal alloy, a reinforced or non-reinforced synthetic material, or any other material having sufficient stiffness qualities. The membrane 102 is made of a material providing it with good ability to bending deformation, and/or good ability to reversible elastic deformation. More specifically, the membrane is comprised of silicone, polyurethane, rubber, any equivalent material, or any combination of these materials. For example, the membrane has a thickness between 2.0 and 6.0 mm, while good results can be obtained with a thickness between 3.5 and 4.5 mm. The fluid 104 may be a liquid or a gas. Good results can be obtained in cases in which the fluid 104 is oil. This fluid, i.e., oil, in this case, has the advantage of being capable of being heated to various temperatures, in particular high enough to melt the hot-melt yarns involved in forming the shells 21, 31, as has been seen above. For example, the oil is heated to temperatures between 120 and 210 degrees Celsius, while good results can be obtained for temperatures between 140 and 180 degrees. In this case, the active surface 105 of the head operates at a temperature between 120 and 140 degrees Celsius, thereby making it possible to melt the yarns 65, 66, 67, 68, 69 only as appropriate for affixing them to one another. The time of application of a head on the last 73, when the shells are in position, is between 90 and 240 seconds, while good results can be obtained for hot-pressing application times between 150 and 220 seconds.

In practice, to implement the manufacturing method, the hot oil is placed in the container 103 closed by the membrane 102. For example, inlets and outlets are provided for adjusting the amount of oil, and heating devices for adjusting the temperature of the oil in the container. The heads are applied to the last 73, or are otherwise spaced therefrom by any appropriate technology. For example, the use of pneumatic jacks 106 is suitable. The pneumatic jacks are all designated here by the reference numeral 106 for reasons of convenience.

All FIGS. 10-27 show that the membrane 102, in most cases, has a convex active surface 105. Thus, when a head 101 takes support on the last 73 to exert hot-pressing on the shell(s), the membrane 102 conforms to the shape of the last. The convex curvature assumed by the membrane 102 when spaced from the last 73 becomes concave when applied to the last. This enables the active surface 105 of the head 101, which is also the active surface of the membrane 102, to conform to the shape of the last 73 and thus to the shape of the shell(s) 21, 31, in order to properly apply of the shells onto the last. This shape-conforming effect makes it possible to obtain an even surface for the shell(s). In other words, the outer surface of the article footwear 1 does not have any folds, which is synonymous with quality. Because it has a deformable active surface, as has just been seen, the head 101 can be considered to be a deformable pad.

As can be understood in particular with reference to FIGS. 28-30, the machine 91, 92 comprises a plurality of stations 95, 96, 97 in a closed path arrangement. This makes it easier to use the machine with limited manpower.

For the machine 91 shown in its entirety in FIGS. 28 and 29, the distribution of the manufacturing stations 95, 96, 97 is horizontal, thereby facilitating maintenance. The machine 91 includes a loading station 111, provided to receive a last 73, covered by the constituent elements of the article of footwear when the machine is in the production phase. Similarly, the machine 91 comprises an unloading station 112, provided for the removal of the last 73, which was positioned beforehand in the machine. This facilitates the use of the machine 91.

For the machine 92 shown in FIG. 30, the distribution of the manufacturing stations 95, 96, 97 is vertical; thereby reducing the machine space requirement. It is noted that a plurality of lasts 73 are rotatably mounted on the same horizontal axis. The rotation of the lasts 73 enables them to move from one manufacturing station to another. It is therefore possible to perform a manufacturing step for one last at the same time as another manufacturing step for another last. Additionally, it is generally noted, with reference to all FIGS. 10-30, that each manufacturing station 95, 96, 97 comprises at least one head 101 provided to exert the hot-pressing, the head having an elastically deformable portion 102. This enables each station to benefit from the advantages of the technology provided by the invention.

In any case, the invention is made from materials or devices known to one with ordinary skill in the art. For example, the structure of the machine 91, 92 may be essentially comprised of metal elements that are welded and/or affixed to one another by screwing, nesting, or other suitable techniques.

The invention is not limited to the embodiments described above, and includes all technical equivalents that fall within the scope of the claims that follow.

In particular, it may be provided to vary the number of steps of the method, that is to say, to shape the shells 21, 31 with a number of steps other than three. Similarly, it may be provided to vary the number of stations on a machine, or to not use all of the stations. 

1-30. (canceled)
 31. Method for manufacturing an article of footwear having at least one shell having a shape set by external heating, the manufacturing method comprising: as a reference step, positioning a first shell on a last, the first shell comprising at least one at least partially hot-melt and thermoformable material, the last extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a base to a top; and following the reference step, at least one manufacturing step comprising at least one operation of hot-pressing at least a portion of a surface of the first shell while the first shell is arranged on the last.
 32. Manufacturing method according to claim 31, wherein: the first shell comprises yarns linked to one another mechanically.
 33. Manufacturing method according to claim 31, wherein: the reference step further comprises positioning a second shell on the last, the second shell comprising at least one at least partially hot-melt or thermoformable material; and the hot pressing operation of the at least one manufacturing step is performed on at least a portion of a surface of the second shell while the second shell is arranged on the last.
 34. Manufacturing method according to claim 33, wherein: the second shell comprises yarns linked to one another mechanically.
 35. Manufacturing method according to claim 31, wherein: the hot pressing of the at least one manufacturing step causes a change of state and/or adhesion of a portion or an entirety of a constituent material of the at least one shell.
 36. Manufacturing method according to claim 31, wherein: the reference step further comprises positioning a reinforcing structure on the last.
 37. Manufacturing method according to claim 31, wherein: the at least one manufacturing step comprises two operations of hot-pressing at least a portion of the surface of the last.
 38. Manufacturing method according to claim 31, wherein: the at least one manufacturing step comprises an operation of hot-pressing the rear end of the last, and an operation of hot-pressing the front end and top of the last.
 39. Manufacturing method according to claim 31, wherein: the at least one manufacturing step comprises an operation of hot-pressing the lateral side of the last, and an operation of hot-pressing the medial side of the last.
 40. Manufacturing method according of claim 31, wherein: the at least one manufacturing step comprises an operation of hot-pressing the base of the last, and an operation of holding the top of the last.
 41. Manufacturing method according to claim 31, wherein: the at least one operation of hot-pressing of at least one manufacturing step comprises at least one manufacturing step further comprises: a first manufacturing step comprising an operation of hot-pressing the rear end of the last, and an operation of hot-pressing the front end and top of the last; a second manufacturing step comprising an operation of hot-pressing the lateral side of the last, and an operation of hot-pressing the medial side of the last; and a third manufacturing step comprising an operation of hot-pressing the base of the last, and an operation of holding the top of the last.
 42. Manufacturing method according to claim 37, wherein: for each manufacturing step, the two operations of hot-pressing at least a portion of the surface of the last are performed simultaneously.
 43. Manufacturing method according to claim 31, wherein: the at least one manufacturing step comprises at least one operation of holding the last.
 44. Manufacturing method according to claim 31, wherein: the at least one operation of hot-pressing is exerted by a head having an elastically deformable portion.
 45. Manufacturing method according to claim 44, wherein: the head comprises a container closed by a membrane, the membrane forming the elastically deformable portion, and the container housing a fluid.
 46. Manufacturing method according to claim 45, wherein: the membrane has a convex active surface.
 47. Article of footwear manufactured by the manufacturing method according to claim
 31. 48. Machine for manufacturing an article of footwear, the machine comprising: at least one manufacturing station arranged to perform at least one manufacturing operation on a last, the last extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a base to a top, wherein, the manufacturing operation comprises hot-pressing at least a portion of the surface of the last.
 49. Machine according to claim 48, wherein: the at least one manufacturing station comprises a plurality of stations in a closed path arrangement.
 50. Machine according to claim 48, wherein: the at least one manufacturing station comprises a manufacturing station arranged to perform an operation of hot-pressing the rear end of the last, and an operation of hot-pressing the front end and top of the last.
 51. Machine according to claim 48, wherein: the at least one manufacturing station comprises a manufacturing station arranged to perform an operation of hot-pressing the lateral side of the last, and an operation of hot-pressing the medial side of the last.
 52. Machine according to claim 48, wherein: the at least one manufacturing station comprises a manufacturing station arranged to perform an operation of hot-pressing the base of the last, and an operation of holding the top of the last.
 53. Machine according to claim 52, wherein: the at least one manufacturing station comprises: a first manufacturing station arranged to perform an operation of hot-pressing the rear end of the last, and an operation of hot-pressing the front end and top of the last; a second manufacturing station arranged to perform an operation of hot-pressing the lateral side of the last and an operation of hot-pressing the medial side of the last; and a third manufacturing station arranged to perform an operation of hot-pressing the base of the last and an operation of holding the top of the last.
 54. Machine according to claim 49, wherein: the manufacturing stations are horizontally distributed.
 55. Machine according to claim 49, wherein: the manufacturing stations are vertically distributed.
 56. Machine according to claim 48, further comprising: a loading station.
 57. Machine according to claim 56, further comprising: an unloading station.
 58. Machine according to claim 48, wherein: each manufacturing station comprises at least one head configured to exert the hot-pressing, the head having an elastically deformable portion.
 59. Machine according to claim 58, wherein: the head comprises a container closed by a membrane, the membrane forming the elastically deformable portion, the container housing a fluid.
 60. Machine according to claim 59, wherein: the membrane has a convex active surface. 